We haven't reviewed SCSI drives since November
last year. Moreover, it is being discussed now whether such reviews are topical
at all. That is why if you have pros or cons such reviews of SCSI drives or comments
on how they should look like, please, send them here. In my opinion, people buying
SCSI drives are well aware of what tasks they are going to be used for, that is
why such reviews should contain less analeptics and more facts because competent
users are able to draw conclusions themselves. But all your suggestions are welcome.
Well, this review is supplemented with "unfiltered" Intel IOMeter results. It
is possible that some people are interested not in average but in the maximum
response time etc.

So, we have tested a 18GB Ultra160 SCSI drive from the IBM Ultrastar
36Z15 line - IC35L018UWPR15. The platters are glass substrate; the DFT
(Drive Fitness Test) is supported, as well as the load/unload ramp technology).

The principle of operation of this device can be understood from the picture taken
from the company's site (www.ibm.com). For more
information on technologies used in drives of this line can be found here.
The drive looks attractive :)

The drive will be compared with 15,000 models reviewed last time
- a model from the Seagate Cheetah X15 36LP line: ST336752LW and one from
the Fujitsu MAM3xxx line: MAM3367MC. Below is a table of the specified
characteristics of these lines.

Fujitsu MAM3xxx

Seagate Cheetah X15 36LP

IBM Ultrastar 36Z15

Capacities (GB)

18.4
36.7

18.4
36.7

18.4
36.7

Heads

4/8

4/8

4/8

GB/Head

4.6

4.6

4.6

RPM

15000

15000

15000

Seek Time Average (ms)

3.5

3.6

3.4/4.2

Average Latency (ms)

2.00

2.00

2.00

Internal Data Rate (Mbits/sec)

320-710

522-709

453-647

Sustained Throughput (MB/sec)

-

51-69

36.6-52.8

Buffer Size (MB)

8

8

4

Interface

Ultra160

Ultra160/Ultra320

Ultra160/Ultra320

Height (inches)

1.0

1.0

1.0

Sound Power (Bels, Idle)

3.6/3.9

3.5

3.8/4

Typical Power Draw (W, Idle)

9.5/11.5

10.5/11.5

11/13.5

The IBM's model doesn't look impressive as compared with the contestants
- it yields to them in almost all parameters except the seek time of the
18GB model. But, as you know, each manufacturer has its own technique of
measuring parameters, that is why let's turn to the tests.

Tests

Testbed:

processor: Intel Pentium III 800EB

mainboard: ASUS CUSL2-LS (i815, Adaptec 7899 Ultra160)

memory: 256 MB PC133 SDRAM

video: integrated (i815)

system disc: IBM DTLA-307015

OS: Windows 2000 Pro SP2

Test software:

ZDLabs Winbench 99 1.2

HDTach 2.61

Intel IOMeter

For the Winbench the drive had one partition of FAT32 and NTFS. For other
programs all information on partitions was deleted. The Winbench and HDTach
tests were fulfilled three times and the results were averaged. Time of
operation of one template for each load in the IOMeter was set to 10 minutes.

Access time

All three tests were used to measure the access time. In the IOMeter
test we took the Average Response Time for the 100% random read template
at Queue Depth equal to 1.

On the whole, the results coincide with the specs - the IBM is ahead.
The ZD WinBench 99 test gives results closest to the specs.

Transfer rate

The HDTach provides average results of read/write speeds.

Nothing unexpected so far - the IBM falls behind its competitors. Let's
take a look at the linear read speeds at the beginning and end of the disc
obtained with the ZD WinBench.

Well, it was possible not to use these tests - it was enough to
look at data in the table. We got nothing new. But, still, let me show
you a diagram of the linear reading of the tested disc.

IBM IC35L018UWPR15

Well, it's time to turn to more informative tests.

Ziff-Davis WinMarks

With the FAT32 the Ultrastar 36Z15 catches up with the Fujitsu MAM3xxx,
and with the NTFS it beats the latter.

Now the synthetic tests:

Intel IOMeter

These results are very similar. In case of the maximum loads the Ultrastar
loses (especially when the Server and Database templates are used). The
complete results for the Server, Workstation, Database, Streaming Read/Write,
Random Read/Write templates are attached (csv
file, Zip archived - 7.818 bytes).

Temperature

Unfortunately, we can't compare correctly the obtained results with the previous
ones for this parameter because today even an air-conditioner doesn't help...
With the same temperature measurement technique we got 48 degrees C.

Acoustic characteristics

I didn't work much with SCSI drives before, that is why I have nothing
to compare with. But it is still much louder than IDE drives :)

Conclusion

The performance of the IBM Ultrastar 36Z15 hasn't increased much, but it
was clear from the specification. Nevertheless, fans of IBM can now get
a 15K rpm model. I think this was the aim - to extend the range of their
models at the expense of the elite class. And performance percentage is
for you to think of :)